The invention relates to apparatus and methods for securing a flow control device in an open position. In one embodiment of the invention, a shiftable valve member located in a conduit is securable in an open position.
In fluid flow operations, it is often desirable to secure a flow control device in an open position. Conventional oil and gas well operations, for example, sometimes warrant securing a shiftable valve member in an open position. For a specific example, it may be desirable or necessary to secure, or xe2x80x9clock openxe2x80x9d, a conventional flapper type safety valve located in a well tubing string in an open position, such as when the valve malfunctions or to allow the performance of well servicing operations through the valve assembly.
Locking devices for flow control devices have been proposed. For example, U.S. Pat. Nos. 3,786,865 and 3,786,866 to Tausch et al., U.S. Pat. Nos. 4,624,315 and 5,127,476 to Dickson et al., U.S. Pat. Nos. 4,411,316 and 4,356,867 to Carmody and U.S. Pat. No. 4,723,606 to Vinzant et al. involve reciprocating or longitudinally movable lockout sleeves for locking flapper valves in an open position.
U.S. Pat. No. 4,577,694 to Brakhage, Jr., U.S. Pat. No. 4,967,845 to Shirk and U.S. Pat. No. 4,542,792 to Akkerman involve valve locking devices that must be run in, or inserted into the well conduit within which the valve assembly is located. U.S. Pat. No. 4,577,694 discloses a locking spring band for permanently locking a flapper valve in an open position. Upon insertion into the conduit and valve assembly, the spring expands peripherally to lock the valve member in an open position. U.S. Pat. No. 4,542,792 uses a locking wedge deliverable with a removable auxiliary device and securable in a ball type safety valve mounted in the conduit for permanently locking the safety valve in the open position. In U.S. Pat. No. 4,967,845, a lock open plug is run into the housing of an axially reciprocating safety valve to secure the plug in an open position.
With respect to each of the above-cited patents, it is important to understand that the features mentioned above are merely examples of features disclosed in the patents. There are numerous other features disclosed in each patent in addition to the features mentioned herein. The additional features can be readily understood from a thorough review of each respective patent. The brief discussion above is included only to introduce the subject matter of the patents and not to distinguish the same from the present invention. Therefore, it is the patent applicant""s intent that the brief remarks about the cited patents above not, in any way, limit or affect the scope of any of the appended claims merely because of their mention herein. A comparison of any of the above-cited patents with the invention of any of the appended claims should involve a comparison of all the features of the cited patent together compared with the entirety of the selected claim(s).
In considering existing technology for securing a flow control device in an open position, there remains a need for apparatus and methods having one or more of the following attributes: an apparatus that requires or occupies minimal or no additional length in the flow control device or the conduit within which the flow control device is located; an apparatus contained in, or internal to, the flow control device; an apparatus that is unaffected, or minimally affected, by environmental variables, such as hydrostatic pressure; an apparatus that is cost effective to manufacture, assemble and use, is simple and durable in construction and use and/or includes a minimal quantity of additional parts; an apparatus that is unlikely to be dislodged, or accidentally engaged, due to contact or force from the passage thereby of other devices, or the flow thereby of fluid and/or material.
In accordance with the present invention, certain embodiments involve an apparatus capable of retaining a shiftable valve member in an open position, the shiftable valve member being disposed in a valve housing and moveable between at least one open and at least one closed position relative to a bore in the housing. These embodiments include a locking sleeve and at least one anchor. The locking sleeve is disposed in the valve housing and movable at least partially around the circumference of the bore from at least a first position to at least a second position. When the locking sleeve is disposed in the first position, the locking sleeve allows movement of the shiftable valve member between its open and closed positions. When the locking sleeve is disposed in the second position, the locking sleeve causes the shiftable valve member to be retained in an open position and prevents movement of the shiftable valve member into a closed position. The at least one anchor is engageable with the locking sleeve and capable of at least temporarily holding the locking sleeve in at least one of its first and second positions.
The shiftable valve member may be a flapper valve member disposed in a subsurface well conduit and the locking sleeve may have a semi-circular shape. The locking sleeve may be movable back and forth between its first and second positions. A shifting tool insertable into the bore, engageable with the locking sleeve from within the bore and capable of rotating the locking sleeve between the first and second positions may be included.
The anchor may include at least one resilient urging member and at least one rigid member, the rigid member engageable between the resilient urging member and the locking sleeve to at least temporarily hold the locking sleeve in the second position, or the first and second positions. Further, the locking sleeve may include at least first and second notches, the at least one rigid member may include a ball and the at least one resilient urging member may include a spring, whereby the ball engages the second notch when the locking sleeve is disposed in the first position and the ball engages the first notch when the locking sleeve is disposed in the second position.
At least one anchor may be capable of holding the locking sleeve in the first position and at least one anchor may be capable of holding the locking sleeve in the second position. The at least one anchor may include a ratchet mechanism capable of at least temporarily holding the locking sleeve in its at least first and second positions. The anchor(s) may include a clutch mechanism, whereby the clutch mechanism is capable of at least temporarily holding the locking sleeve in the at least first and second positions. The at least one anchor(s) may include a shear pin releasably engageable with the locking sleeve when the locking sleeve is in the first position. The locking sleeve may be engageable from above the locking sleeve for moving the locking sleeve between the first and second positions.
Certain embodiments of the present invention involve a lock-open device for locking a flapper valve member in an open position, the flapper valve member disposed in a valve housing and being useful in an underground oilfield tubular. The valve housing has a height and a longitudinally extending bore through its height, and the flapper valve member is hingeably moveable between at least one open and at least one closed position relative to the bore. These embodiments include a locking sleeve having a semi-circular shape and disposed in the valve housing at the same general height as the flapper valve member. The locking sleeve is movable within a circular path at least partially around the circumference of the bore from at least a first position to at least a second position. When the locking sleeve is disposed in the first position, the locking sleeve does not engage the flapper valve member. When the locking sleeve is in the second position, the locking sleeve engages the flapper valve member and retains it in an open position. These embodiments also include at least one anchor engageable with the locking sleeve and capable of at least temporarily holding the locking sleeve in at least one of the at least first and second positions. The locking sleeve may be capable of permanently holding the flapper valve member in an open position. Alternately, the locking sleeve may be capable of temporarily holding the flapper valve member in an open position, whereby the locking sleeve is movable back and forth between different positions.
Various embodiments of the present invention involve a safety valve for use in an oilfield tubular. The safety valve includes a housing having a longitudinal bore extending therethrough, and a flapper valve member disposed in the housing and being hingeably movable relative to the longitudinal bore. The flapper valve member has an open position allowing fluid flow through the longitudinal bore and a closed position disallowing fluid flow through the longitudinal bore. These embodiments also include a rotatable lock-open sleeve disposed in the housing. The rotatable lock-open sleeve is movable in a circular path at least partially around the circumference of the longitudinal bore and adjacent to the flapper valve member, and is capable of holding the flapper valve member in its open position. At least one anchor engageable with the lock-open sleeve and capable of at least temporarily holding the lock-open sleeve in at least one of the first and second positions may be included.
Embodiments of the present invention involve a subsurface safety valve with lock-open capability and useful in an oilfield tubular, and which includes a housing having a longitudinal bore extending therethrough and valve closure means mounted in the housing for allowing and disallowing fluid flow through the longitudinal bore. The valve closure means had an open position, which is capable of allowing fluid flow through the longitudinal bore, and a closed position, which is capable of at least partially blocking fluid flow through the longitudinal bore. A lock-open means for securing the valve closure means in the open position is also included. The lock-open means is permanently disposed in the housing and movable in a generally circular path within the longitudinal bore. These embodiments may also include means for rotating the lock-open means between at least first and second positions, and means for at least temporarily holding the lock-open means in at least one of its first and second positions.
In accordance with the present invention, embodiments of methods of securing a shiftable valve member in an open position with the use of a locking sleeve, the shiftable valve member and locking sleeve being mounted in a housing having a longitudinal bore extending therethrough, the shiftable valve member being moveable between at least one open and at least one closed position relative to the bore and the locking sleeve being rotatable at least partially around the circumference of the bore from at least a first position to at least a second position, the shiftable valve member being retained in an open position when the locking sleeve is in the second position, include moving the locking sleeve in a generally circular path from its first position in the direction of its second position and moving the shiftable valve member into an open position. The method also includes moving the locking sleeve in a generally circular path into its second position and securing the locking sleeve in its second position, thereby securing the valve member in its open position. The method may include inserting a shifting tool into the bore, engaging the shifting tool with the locking sleeve and actuating the shifting tool to rotate the locking sleeve.
The method may include disengaging at least one anchor from the locking sleeve to allow the locking sleeve to be moved out of its first position, and engaging at least one anchor with the locking sleeve in its second position. Yet further, the method may include disengaging at least one anchor from the locking sleeve when the locking sleeve is in its second position and moving the locking sleeve in a generally circular path out of its second position. Even further, the method may include moving the locking sleeve into its first position and engaging at least one anchor with the locking sleeve to hold the locking sleeve in its first position. The shiftable valve member may be a flapper valve member disposed in a subsurface oilfield tubular and the locking sleeve may be a semi-circular member. Of course, the sequence of events described above need not be performed in the precise order listed above.
Accordingly, the present invention includes features and advantages which enable it to substantially advance the technology associated with securing flow control devices in an open position. Characteristics and advantages of the present invention described above, as well as additional features and benefits, will be readily apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments and referring to the accompanying drawings.